OK, all good input.
I am now thinking about using the 240 injectors with the rising rate FPR. Just lowering the base pressure (I'll test the spray patterns).
As for the WOT comment, I am not sure it's true. WOT has nothing to do with boost. The superchargers that Frank & I are using are similar, as in that they both have a bypass valve located in them. The valve is vacuum operated from the throttle body to open up under high vacuum operating conditions (idle, cruise) & close during low vacuum conditions (acceleration & WOT).
I personally think that with the bigger injectors with lower base pressure & a rising rate FPR, I should be able to keep within the ECU parameters. The manufacturers of rising rate FPR's are pretty savvy to boost applications & can tune them to work right. I will find out if they are a linear rate of rise & report back...

Thanks for all of the input...

Ed

From Bell Engineering:

http://www.bellengineering.net/Pages/products_MRFPR_Instruction.html

Adjusting the 2035
Three adjustment are necessary with this regulator. NA engines that are subsequently fitted with forced induction often exhibit extreme leanness in the range of 4 inches of vacuum to approximately 3 psi boost. The cause for this is that the turbo/sc can achieve atmospheric pressure in the manifold prior to the throttle being fully open. Without full opening, the throttle position sensor will not send the proper signal to the ECU, hence, a lean condition occurs. To counter this weÆve made the ôonsetö of fuel pressure rise adjustable. The 2035 can actually start raising the fuel pressure prior to being under boost. This is accomplished by the center screw in the R/R section of the regulator. The actual rate of gain of the fuel pressure rise relative to the boost is under the control of the needle valve at the side of the R/R section. Adjusting the static fuel pressure for normally aspirated operation is the responsibility of the screw at the end of the 1/1 section. In all installations, we urge tuning be aided with an air/fuel ratio meter.

After the regulator is in place, all signal lines attached and the check valve in position, adjustment can begin.


The vacuum control of 1/1 regulation has been set by BEGI to 36 psi at atmospheric pressure (zero manifold). The engine should start and idle properly. Start the engine and inspect for fuel leaks. Correct any leaks before proceeding further.


First adjustment:

Check the idle fuel pressure. It will be less than 36 psi due to the manifold vacuum of idle RPM. Verify the 36 psi setting by pulling the signal line from the 1/1 side of the regulator. It is necessary to pinch or plug shut the removed signal line to read the fuel pressure, as the vac leak will upset the R/R part of the regulator. If the gauge reading is not 36 psi, trim it to 36 with the 1/1 screw. Then snug the jam nut and replace the vac signal line.


Second adjustment:

The second adjustment of fuel pressure is the onset of gain. This represents the fuel pressure as the manifold conditions cross from vac into boost. This is done at idle. To simulate passing through the zero point, the vacuum line must be removed from the R/R side. The regulator then sees atmospheric pressure as a signal, the same as zero on the boost gauge. Control of the fuel pressure at the zero point is by the Allen screw in the center of the R/R side of the regulator. Clockwise on the screw will raise the pressure. Once adjusted, plug the vacuum line back onto the regulator and observe the fuel pressure drop back to the stock figure. A suggested starting point pressure 48 to 50 psi. Please understand, this will vary from engine to engine, and is not a magic number. The ômagicö number is whatever pressure your vehicle requires to pass thru the boost onset without the lean flat spot. It is not unusual to see pressure anywhere from 40 psi to 55 psi. Use whatever works best.


Third adjustment:

Adjust the R/R needle valve when testing under boost.


The maximum fuel pressure is controlled by the needle valve and must be determined while driving the car under boost. Start with the needle valve closed, which is fully clockwise.


Pressure calculation:
The fuel pressure required increases with the square of the boost pressure ratio:
Example: 6 psi boost is a pressure ratio of 1.41. With stock fuel pressure of 36 at zero boost, than:

Needed fuel pressure = ( PR2 x 36) + boost = (1.412 x 36) + 6 = 77.5 psi



The second adjustment, the needle valve, controls the rate of gain of fuel pressure versus boost pressure. The lowest rate of gain is with the needle valve fully open, the highest, fully closed. Clockwise closes the needle valve. Figure 2025 offers a typical guide to fuel pressure versus boost pressure. Caution: There is a vague limit that exists with regard to the maximum possible fuel pressure. The industry Barbara S (BS) of injectors jamming at 50 psi and the flow not increasing with pressure is not correct. It is possible for a very large injector (90 + lbs/hr) to jam at 100+ psi of fuel pressure. At anything less than that, jamming is not going to happen.

That's right, Ed. Since neither of us have any experience with this engine/ECU/FMU, it's premature to say we WON'T have tuning issues, but the problem of the injector size flooding the mixture on part throttle/partial boost would seem to require very large injectors that are outside the ECU's lookup tables. I don't know the lookup table parameters in our ECU, so it's impossible to say the combination will work. The reason I chose the 240 cc/min injectors is to try to stay within the ECU's capability - initially, I'm more concerned with idle and low-speed operation than partial boost at cruise speeds. If I can get the engine to idle correctly, the injector size seems right for enough fuel at higher power levels without asking for a super high fuel pressure. In fact, I hope to be able to raise the base pressure enough to run the injectors at WOT without raising the fuel pressure rate at all under boost - the ideal solution if the ECU can do the job. If you use the injector size calculator I sent you, plug in 200HP as the target with .600 brake specific fuel consumption, 85% injector duty cycle, you'll see that 45psig rail pressure is sufficient to flow enough fuel at WOT with 240cc/min injectors - and would not require the FMU if the idle quality is controllable in the ECU. Obviously, the key is in keeping power gain expectations to a reasonable level and not trying to make a drag car out of an otherwise very nice truck.

If you read the info on the setup Darin used as a model to build his system, you'll see that those engines are running large amounts of boost and up to 550 cc/min injectors - way past the OE stock 290 cc/min injectors - and making a reported 300 flywheel HP on ~13psi boost pressure.

Darin's statement about the ECU not being able to deal with an FMU on part throttle/partial boost is probably correct with the setup using really large injectors. I would also imagine they have rich idle issues, but I don't know that. I won't know what the 3.0L will do until it's running. In any event, the lower boost level and smaller injectors will hopefully keep it in the tuning range.

Frank

Stealth MAF's are Karman vortex types. They have a vortex generator and a pressure transducer and an A/D converter. The vortex generator makes little whirlwinds in numbers proportional to mass air flow. The more vortexes, the greater the frequency of the pressure pulses on the transducer, which outputs a sine wave a/c output to the A/D, which turns it into a square wave digital output with the same freq. and sends it to the ecu as a digital freq. Don't know how the ecu processes it for lookup. (I just found the Stealth Technical Manual ftm .pdf)

MS2 has the ability to control spark, and will run a Ford EDIS just fine, and you can forget the maf matching.

KISS and speed density are my systems....

Fasteddie, could you PM or post the website of that Stealth manual? If I can make this Diamante MAF work, alot of peeps can benefit from less flow restriction.

I am thinking about the MS2, but will try it on a junker car, until I understand it fully.

Thanx....

Ed

I can't find it in my history, but google stealth316 and you should find it. I have the file, but both my burners are lost to the cybermind, and, like Frank, I'm too old to catch up on computers, and at 26kbaud, you'd lose interest before I could email it, unles you're coming to ATL anytime soon?

OK, due to Fasteddie's help, I think I have a partial answer. My 89 3.0 Raider has the Karmann Vortex type MAF, as well as the Stealth/3000GT/Diamante(mine) unit. They both have the Barometric sensing unit, as well as the air temp sensor.

I will try to get schematics & specs for both. If it's possible & they are somewhat compatible, the Diamante looks to have about 5 TIMES the flow area !!!

Also, when I supercharge the engine, I am thinking about putting the temperature sensor inside the intake plenum to accurately measure the compressed air temperature.

ED

Glad I could help.

From the same source I may have found the fabled "4bolt main" block. It's not quite what I expected. It has the same integrated main bearing cap-girdle system, with added beef in the beams in the cap/girdle to increase rigidity, and some added bolt down clips on the center 3 mains. Never seen that approach before. Also has mounts for a stock det sensor bracket in the valley and an extra oil drain back hole in the head. I want that block.

Check the Stealth316 page and DSM for ECU related changes. I would think you would want the ECU for the Stealth engine. I do not see how you could set up the Mitsubishi ECU with the Stealth engine. You can not reprogram the 89-91 ECU that I know. I have gone thru a couple of ECU and have laptop that I hook up to the ECU just to get performance data. Cap failure was the problem not the laptop. I would think you would want something like that to due your tuning with. Let me know I will send you the links. I have only tested this with my 91 Monty. I can not reset codes with this setup, but I can monitor faults, turn on and off solenoids, fuel pump relays. This setup allows you drive around and monitors selected parameters.(RPM, SPEED, MAF, O2) You can graph it or save it to a CVS file that you can use in excel.(DYBG)